Implantable medical devices utilize electrical power to function when performing a medical task such as electrical stimulation therapy. In order to provide the implantable medical device with autonomy from any external power source, an internal battery may be included to provide the electrical power. Conventionally, the battery is positioned within a hermetically sealed enclosure together with circuitry for controlling the operation of the medical device.
The battery used for medical devices has an anode terminal and a cathode terminal but may also have an electrical potential relative to the anode and/or cathode that is present on a housing of the battery, particularly where the battery is a case neutral design. When the battery is mounted within the hermetically sealed enclosure of the implantable medical device, the battery housing is electrically isolated from the anode and/or cathode terminals as is appropriate. The battery is also electrically isolated from other electrical components of the medical device including an enclosure of the medical device and also electrical stimulation outputs. Likewise, the battery is isolated from related electrodes present on a medical lead that may be electrically connected to the electrical stimulation outputs.
While having the battery within the hermetically sealed enclosure provides electrical isolation for the battery, there is a lack of modularity. For instance, if a larger sized battery is desired, the medical device that is designed to house the smaller battery may not be able to easily accommodate the larger battery. Thus, conventional designs do not provide adequate modularity while providing electrical isolation of the battery housing.